Mystery Sci Fi Prop Helmet

I think we can all be agreed that this is a pretty cool looking helmet from a late 70s/ early 80s sci fi film. It also looks like a Pilot's helmet to me, owing to those triangles just above the visor.
It's entirely possible it was used by an extra in a background shot but I'd still like to find out! Ewbanks will be auctioning the helmet at the end of October and the only other information they can provide is that it looks professionally done.
Estimated value is £80-120.